Heavy duty trucks and trailers (hereinafter "trucks") typically have rear wheels which are mounted on a suspension system secured to the frame of the truck by frame hangers. Axle housings are coupled to the frame hangers by welding or other attachment means. The axle housings mount rear wheel axles which may be a single axle or two axles depending upon the size of the truck. Typically, there are two axle at the rear of a heavy duty truck and each end of each axle has an axle housing.
A walking beam is provided on each side of the truck, respectively. The ends of each walking beam are provided with respective bushings to absorb the shock applied to the wheels as they move over rocks and cause deflection of the walking beams relative to the suspension system of the truck. The ends of each walking beam are coupled to respective axle housings.
The bushings at the ends of a walking beam typically wear out over time and must be replaced. Until now, the replacement of the bushings has required a substantially complete disassembly of the axle housings from the walking beam of the vehicle suspension system. Such disassembly requires a large amount of time and considerable labor. Moreover, the truck is out of service during this period of disassembly and replacement of a bushing. Such down time of the truck represents a loss of profits to the owner. Thus, it is desirable that such disassembly time and replacement time be minimized to cause the truck to be in service more often and without sacrificing the quality of service in disassembly and replacement. A need exists for improvements in the structure for mounting the bushings on the ends of the walking beam so that the bushings can be quickly and easily replaced in a shorter time than is conventionally possible while at the same time providing a quality mount for the bushings and a long useful operating life for the walking beam itself. The present invention satisfies this need.
Disclosures relating to this general subject matter include the following references: U.S. Pat. Nos. 3,043,606, 3,069,184, 3,202,439, 3,323,811, 4,500,110 and 4,775,166, British Patent 1,373,613 and German Patent 1,505,342.